Tests - Update product analytics project settings flow

What does this MR do and why?

Project settings UI for analytics has changed and no longer has "expand" button.

This changes are to update the tests to work fine with new flow. Removed page object for Data Sources and moved it's content to Analytics Settings page object.

Note: These tests only run in Product Analytics devkit pipelines at the moment.

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshot of the tests passing in Product Analytics devkit with GDK and Gitlab QA images built from this branch.

The pipeline:

How to set up and validate locally

Instructions on how to run Product Analytics tests locally can be found here.